Coated nail



Patented July 9, 1946 COATED NAIL Willis E. Boak, Burton, Ohio, assignor to The American Steel and Wire Company of New Jersey, a corporation of New Jersey No Drawing. Application February3, 1944, Serial No. 520,929

1 Claim. 1 This invention relates to coated nails of the type having coatings for the purpose of enhancing their frictional resistance to withdrawal after being hammered into wood.

According to the invention, nail coating material is made up consistingby weight of 86 parts 'Cumar of CK grade, 155 parts gilso-nite, 2 to 8 parts plasticizing oil, 475 parts petroleum naphtha, 125 parts asbestine and 75 to 90 parts red oxide of iron. The plasticizing oil may be a semi-drying or slow drying oil such as fish oil or soya bean oil, a refined grade of fish oi] being preferred.

In coating the nails, it is considered preferable to mix the first four of the above constituents together and to pour them into a tumbler into which the nails to be coated have been placed, and to add the asbestine and red oxide of iron separately to the tumbler, the nails then being tumbled for from 3 to 6 minutes as required. The amount of the coatin material used respecting the amount of nails coated depends on the thickness of coating desired, a satisfactory proportion being 2.4 pints of the liquid consisting of the first four constituents per thousand pounds of 8a sinker nails, with the asbestine and red oxide of iron added as required to provide the proportions previously disclosed. The grade of petroleum naphtha must be selected to suit the nail coating operating conditions. the turpentine substitute grade is suitable for very warm conditions, the varnish makers and painters grade is suitable fo more temperate conditions and the dry cleaners grade is suitable for cold conditions.

After the tumbling the nails may be removed from the tumbler and barrelled in the usual fashion. In ordinary plant practice no trouble is experienced with the nails sticking together unduly Thus, mineral spirits of 2 when the proper grade of petroleum naphtha is used.

Evaporation of the naphtha produces finished nails having coatings consisting by weight of 86 parts Cumar of CK grade, 155 parts gilsonite, 2 to 8 parts plasticizing oil, 125 parts asbestine and '75 to 90 parts red oxide of iron.

When these coated nails are driven into wood the rapid movement of the nails relative to the wood produces sufiicient heat to renderthecoatings plastic so that they flow slightly and fill the irregularities in the wood while remaining bonded V V to the nails. The coatings have adequate shear strength so that they will not be torn in half too easily. In addition, the coatings are not readily knocked off during handling and shipping. Nails are frequently carried in the mouth by users and V,

the coating described hereindoes not present a health hazard in this respect. In addition to all this, the constituents of the coating are available at the time of the present war emergency. v

It is to be understood that the principles of the invention are applicableto any metal fastenings of the type that is hammered into wood and the like and frictionally retained therein.

The term Cumar as used herein is intended to designate a synthetic resin mixture ofpolymerized coumarone, indene, and homologous compounds. Cumar is made up in different grades according to specific gravity and melting point. The CX grade has a melting point from 111.2 F. to 129.2 F.

I claim:

A metal fastening 0f the type that is hammered into wood and frictionally retained therein, having a coating consistin by weight of about 86 parts Cumar of CK grade, 155 parts gilsonite, 2 to 8 parts plasticizing oil, parts asbestine and '75 to 90 parts red oxide of iron.

WILLIS E. BOAK. 

